Automatic cutoff valve



ocal ul nuum aliiu Feb. 9, 1943. s. T. HOWARD AUTOMATIC CUTOFF VALVE Filed Aug. 29, 1941 Search Room Patented Feb. 9, 1943 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein, if patented, may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to valves and more particularly to an automatic cut-off valve that will operate to cut off the flow of fuel from a tank or other source of supply should a break develop in the fuel line, that unless the supply of fuel, which is usually under pressure is promptly cut off, will discharge through said break. An instance for which this structure is especially designed is a volatile fuel of a highly combustionable character such as high-test gasoline stored in a tank under pressure and fed to a burner, in this instance the heating unit for the recently developed army portable range.

An object of this invention is to provide an inexpensive and simple structure that will promptly operate and does not depend upon a spring or other means for its operation that will deteriorate and result in failure.

A further object of this invention is to provide a structure that will operate instantly to cut off the flow of fuel from a tank or other source of supply should said supply be abnormally increased by a break in the fuel line between the tank or other supply and the burner.

The above and other objects will appear in the following specification and be finally pointed out in the appended claims.

While a preferred form of the improved valve is shown and described, it will be understood that slight changes in form and final details of structure may be resorted to without departing from the spirit of the invention or fall beyond the scope of the claims.

Similar numerals indicate corresponding parts in all the figures of the drawing in which:

Fig. 1 is a vertical section of a partly fllled fuel tank showing the valve in elevation.

Fig. 2 is a vertical section showing the valve open.

Fig. 3 is a similar view with the valve closed and a break in the fuel line.

Fig. 4 is a detailed perspective view of the fuel check.

Fig. 5 is an enlarged side view of the nipple connecting the pick-up tube and valve body.

Fig. 6 is a longitudinal section of Fig. 5.

Fig. 7 is an elevation of one end of the nipple.

Fig. 8 is an elevation of the other end of the nipple.

Reference now being had to the drawing by numerals, l indicates a fuel supply tank having mit a sufiicient overflow to be dangerous.

a filling tube 2, provided with a captive cap 3. The fuel tank as shown is approximately onehalf full of fuel as seen at 4, the upper portion 5 of the tank having about 40 lbs. pressure of air therein adapted to lift the fuel in the tank through the automatic valve and the fuel line tube 6 to a control valve and burner not shown, the fuel line tube 6 being connected with the automatic valve by union plug 1 and nut 8 in the usual manner.

The automatic valve consists of the body 9 threaded into fitting III which is welded or brazed in place in an opening in the fuel tank I. The body of the valve is provided with a bore ll, screw-threaded at its lower end at l2. Nipple I3 is threaded into the lower end of body 9 and is provided with a bore l4.

Pick-u tube I5 is mounted at its upper end and extends close to the bottom of the fuel tank, the latter providing for the discharge of all of the contents of the tank by air pressure provided in portion 5 of the tank.

Under ordinary conditions the fuel from the tank is lifted through the automatic valve and fuel line 6 to the control valve and from thence to the burner, the latter not being shown. The control valve, as is well known, controls the flow of fuel to the burner which is relatively at a slow rate.

Mounted in the body 9 in bore ll of the valve is the check [6 shown in detail in Fig. 4. The check is of less length than the chamber II and contacts the sides of the chamber at four places as indicated at IT. Between said contacts are flattened surfaces l8 which provide a small passage for the fuel beyond the check. Said check is flattened at its lower end which rests on the upper end of the nipple l3, said nipple at its upper and being provided with radiating grooves l9 adapted to provide small passages for the fuel from the bore of the nipple l3 out to the passages formed by the flattened portions l8 of the check I6. The check I6 is further provided with a coneshaped upper end 20 adapted to be seated in the valve seat 2| when the flow of fuel is cut off from the tank. Said check is further provided in its cone-shaped surface 20 with a small flattened portion 22 adapted to permit a very small amount of fuel to pass beyond the check and permit the location of the leak in the fuel line but not per- The lower end of the check is provided with a cutaway portion 23 which further provides for a slight circulation of the fuel up through the valve when the normal supply of fuel is required and no abnormal flow as caused by a break in the line exists.

The operation of the improved automatic check valve is obvious since it will be understood that when the check I6 is resting at the lower end of chamber ll of the valve body, sufllcient fuel is permitted to pass through the valve and out through the fuel line to the burner, said flow of fuel, as stated above, being controlled by the control valve, not shown, said back pressure from the control valve causing the check to occupy the lower position referred to with its cone-shaped upper end remote from seat 2 I at the upper end of the chamber in the valve body. When the flow of fuel up through pick-up pipe through nipple l3 out to the side passages, provided by the flattened surfaces l8 of the check and up through the upper end of the valve body and out through the pipe line is normal, said flow is sufficient to provide the necessary fuel to the burners. The instant a break develops, as illustrated in pipe 6 at 24, the abnormal flow of fuel through the automatic valve will cause the check I 6 to rise and cut off the flow of fuel through the valve and remain in that position due to the pressure in the tank until the back pressure of the control valve and that within the tank equalize and the check then drops to its normal lower position and again permits the normal flow of fuel required by the burner to pass through the automatic valve and the fuel line to the burner through the control valve.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. An automatic fuel cut-off valve having a body portion and a bore therein provided with a valve seat at its upper end, a check of less length than the length of the bore having a cutaway portion at its lower end and a tapered valve portion at its upper end adapted to seat in said valve seat, said tapered valve portion having a slightly flattened portion adapted to permit the passage of a small amount of fuel when the valve is seated. said check having flattened side portions adapted to provide for normal flow of fuel beyond said check when in its lower position, a nipple mounted at the lower end of the bore of the body portion having a fuel passage therein, radiating fuel grooves in the upper end of the nipple adapted to support the check in its lower position and provide for the normal flow of fuel beneath said check and up through said fuel passages at the sides of the check, said check adapted to normally rest in its lower position and be caused to rise and cut off all but a small portion of the flow of fuel, should a break in the fuel line permit an abnormal flow of fuel beyond the valve, and permit said small portion of the fuel to indicate through the break the location of same.

2. An automatic partial fuel cut-off valve having a body portion and a bore therein provided with a valve seat at its upper end, a check of less length than the length of the bore having a cutaway portion at its lower end and a tapered valve portion at its upper end adapted to seat in said valve seat, said tapered valve portion having a slightly flattened portion adapted to permit the passage of a small amount of fuel when the valve is seated and having flattened side portions adapted to provide for normal flow of fuel beyond said check when in its lower unseated position, a nipple mounted at the lower end of the bore of the body portion having a fuel passage therein, radiating fuel grooves in the upper end of the nipple adapted to support the check in its lower position and provide for the normal flow of fuel beneath said check and up through fuel passages formed by said flattened portions at the sides of the check, said check adapted to normally rest in its lower position and be raised and partly cut off the main flow of fuel should an abnormal flow of fuel occur due to a break or other leak in the line beyond the valve and permit a limited flow of fuel beyond the valve, out through said break to indicate to the operator the location of the break.

STYLES T. HOWARD. 

